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AD-A120 181 ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG--ETC F/B 13/2KAHULUI BREAKWATER STABILITY STUDY, KAHULUI, MAUI, HAWAII. HYDR--ETC(U)JUL 82 D A MARKLE.
UNLASSIFIED WES TR/HL-8 -14 NL
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TECHNICAL REPORT HL-82-14
KAHULUI BREAKWATER STABILITY STUDYKAHULUI, MAUI, HAWAIIHydraulic Model Investigation
by
Dennis G. MarkleHydraulics Laboratory
U. S. Army Engineer Waterways Experiment StationP. 0. Box 631, Vicksburg, Miss. 39180
DvT1CJuly 1982 ~E L C
Final Report ouyt2 9
Approved For Public Release Distribuition Unlimited
Poemae for U. S. Army Engineer Division, Pacific Oceanrr.Fort Shafter, Hawaii 9665
82 t'12 106
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Destroy this report when no longer needed. Do not returnit to the originator.
The findings in this report are not to be construed as an officialDepartment of the Army position unless so designated.
by other authorized documents.
The contents of this report are not to be used foradvertising, publication, or promotional purposes.Citation of trade names does not constitute anofficial endorsement or approval of the use of
such commercial products.
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UnclassifiedSECURITY CLASSIFICATION OF THIS PAGE (Wm.n Does Entered)
READ INSTRUCIONSREPORT DOCUMENTATION PAGE BEFORE COMPLETTING FORM1REPORT NUMBER 2. GOVT ACCESSION NO. 3. RECIPIENT'S CATALOG NUMBER
Technical Report HL-82-14 411~i/_______________4. TITLE (811d Su.bile) S. TYPE OF REPORT & PERIOD COVERED
KAHULUI BREAKWATER STABILITY STUDY, KAHULUI, Final reportMAUI, HAWAII; Hydraulic Model Inetgato 6. PERFORMING ONG. REPORT NUMBER
7. AUTNOR(s) 11. CONTRACT OR GRANT NUMSkER(e)
Dennis G. Markle
9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELENT PROJECT. TASK
U. S. Army Engineer Waterways Experiment Station AR..OkUFjTNM95Hydraulics LaboratoryP.O. Box_631,_Vicksburg,_Miss. 39180 ______________
It. CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE
U. S. Army Engineer Division, Pacific Ocean July 1982Building 230 13. NUMB3ER OF PAGESFort Shafter, Hawaii 96FS8 154
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1S. SUPPLEMENTARY NOTES
Available from National Technical Information Service, 5285 Port Royal Road,Springfield, Va. 22151
19. KEY WORDS (Continue on reverse stde If nocoeareinvmd idenltfy by block number)
Armor units WavesBrealrwatersHarborsHydraulic modelsKahului, Maui, Hawaii
20. AUSTVAcriviet~e , ervee Nh fnieoes) -d i~dit by block nuimbw)A hydraulic model investigation was conducted at geometrically undis-
torted, linear scales of 1:33, 1:36, and 1:40, model to prototype, to evaluatethe stability against wave attack of proposed rehabilitation designs for twoareas, each on the harbor sides of the east and west breakwaters at KahuluiHarbor, Maui, Hawaii. A proposed rehabilitation design for the sea-side slopeof the west break~water at sta 18+50 and the existing sea-side slope protectionon the west breakwater at sta 21+25 also were evaluated for stability against
(Continued)
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UnclassifiedSCURIVTy CLASSIFICATION OF THIS PAGE (Vi Data RhNr.0
20. ABSTRACT (Continued)
wave attack. Where the proposed designs failed, additional tests of alterna-tive plans were conducted until stable design sections were found. All planswere tested for the worst breaking wave conditions that could be produced forthe selected wave periods, water depths, and bathymetry seaward of the testsections.
The existing 19-ton tribars on the sea-side slope of the west breakwaterat sta 21+25 proved to be stable, and six plans (three dolos and three tribar)were found acceptable for the proposed harbor-side slope rehabilitation. Withthe addition oaf a concrete rib cap on the crown of the west breakwater atsta 18+50, 11-ton and 5-ton tribars were found to be stable on the sea- andharbor-side slopes, respectively. For the east breakwater at sta 26+10, 9-tontribars showed very good stability when placed on a 1V-on-2H harbor-side slope.A concrete rib cap was added to stabilize the crown and upper sea-side slope ofthe east breakwater at sta 23+35 and 9-ton tribars placed on a IV-on-2H slopeprovided stable protection for the harbor-side slope. ...
The stabilities of all plans found acceptable ari-dependent upontrenching and/or special placements of the toe armor units, as described foreach alternative design. Model observations also indicated that the harbor-
side armor unit protection should not extend above the breakwater crownelevation any more than absolutely necessary. Tests indicated that it waspreferable to leave a small gap between the concrete rib cap and the upperharbor-side armor protection than to fit a unit in this area if a largeportion of the unit had to project above the crown of the structure.
UnclassifiedSECURITY CLASSIFICATION OF THIS PAOESf 081a Stneet
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PREFACE
The model investigation reported herein was initially requested
by the U. S. Army Engineer Division, Pacific Ocean (POD), in a letter
to the U. S. Army Engineer Waterways Experiment Station (WES) dated
15 December 1980. Funding authorizations by POD were granted in POD
Intra-Army Order PODSP-CIV-81-33 and its Change Order No. 1, dated
13 February 1981 and 14 July 1981, respectively.
Model tests were conducted at WES during the period February 1981
through July 1981 under the general direction of Mr. H. B. Simmons,
Chief of the Hydraulics Laboratory, Dr. R. W. Whalin, Chief of the
Wave Dynamics Division, and Mr. D. D. Davidson, Chief of the Wave
Research Branch. Tests were conducted by Mr. D. G. Markle, Hydraulic
Research Engineer, assisted by Mr. M. S. Taylor, Engineering Technician,
and Mrs. B. J. Wright, Engineering Aid. This report was prepared by
Mr. Markle.
Liaison was maintained during the course of the investigation by
means of conferences, progress reports, and telephone conversations.
Commanders and Directors of WES during the conduct of this study
and the preparation and publication of this report were COL Nelson P.
Conover, CE, and COL Tilford C. Creel, CE. Technical Director was
Mr. F. R. Brown.
Accession For
NTIS GRA&I
DTIC TABUnarmon:,onced ElJustification
By_ _ _Distribution/ OTIC
Availability Codes CPY
Av.21 a-nd/orDist Special
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CONTENTS
Page
PREFACE. .. .................... ......... 1
CONVERSION FACTORS, U. S. CUSTOMARY TO METRIC (SI)UNITS OF MEASUREMENT .. ...................... 3
PART I: INTRODUCTION. .. ..................... 5
The Prototype. .. ....................... 5Purpose of Model Study .. ................... 5
PART II: THE MODEL .. ....................... 7
Design of Model. .. ...................... 7Test Facilities and Equipment. .. ............... 8Model Construction and Testing Procedures .. .......... 8
Modeling local bathymetry .. ............... 8Flume calibration .. ................... 8Methods of constructing test sections. .......... 9Selection of test conditions. .. ............ 11Model operation. .......... .......... 12Methods of reporting model observations and
test results . . . . .. .. .. .. .. .. .. . .13
PART III: DESCRIPTIONS OF EXISTING SECTIONS, TESTPLANS, AND TEST RESULTS .. .......... ...... 14
West Breakwater at Sta 21+25 .. ........... ..... 14West Breakwater at Sta 18+50. .. ............... 21East Breakwater at Sta 26+10 .. .......... ...... 23
Breakwater at Sta 23+35. .. ............... 25
PART IV: CONCLUSIONS. .. ..................... 27
PART V: DISCUSSION .. ...................... 29
TABLES 1-4
PHOTOS 1-100
PLATES 1-22
APPENDIX A: NOTATION
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CONVERSION FACTORS, U.S. LST~j?1ARY TO METRIC (SI)UNITS OF MEASUREMENT
U. S. customary units of measurement used in this report can be
converted to metric (SI) units as follows:
Multiply By To Obtain
-ubic feet 0.02831685 cubic metres
feet 0.3048 metres
miles (U.S. statute) 1.609344 kilometres
pounds (mass) 0.4535924 kilograms
pounds (mass) per cubic foot 16,01846 kilograms per cubic metre
square feet 0.09290304 square metres
tons (2,000 lb, mass) 907.1847 kilograms
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CON., RIOS Swm 900 ATS'4. 0. RAVdILVI
4L. 1. a8V211gb
SILLS EL. 00'
BREAKWATER 0
SECTION A-ALOCAT ION AP
ISLAND Of MAUI1
P AC IFI C a 10 t
0CEAN A'~f INFl NIL%$
- f~4) 2.050FE~l IDE. .00 FEET N
Figure 1. Kabului Haror, a auuMuHwi
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KAHULUI BREAKWATER STABILITY STUDY
KAHULUI, MAUI, HAWAII
Hydraulic Model Investigation
PART I: INTRODUCTION
The Prototype
1. Kahului Harbor is located on the north coast of the Island
of Maui (Figure 1). Kahului, Hawaii, is about 94 miles* southeast of
Honolulu, Oahu, Hawaii. The harbor is protected by two rubble-mound
breakwaters, the 2,766- and 2,315-ft east and west breakwaters, respec-
tively, which were completed in 1931. Since their completion, the
breakwaters have accrued significant damage during several major storms
and have been repaired on numerous occasions using various sizes of
dolosse, tribars, and tetrapods. Concrete caps and/or concrete ribs
have also been added to the heads and portions of the trunks on both
breakwaters. To date, most repair work has been concentrated on the
crowns, heads, and sea-side slopes. The harbor-side slopes have de-
graded to very steep slopes along various lengths of both breakwaters,
and the U. S. Army Engineer Division, Pacific Ocean (POD), is consider-
ing rehabilitation of these areas along with a portion of sea-side slope
on the west breakwater.
Purpose of Model Study
3. The purposes of this breakwater stability study were as
follows:
a. Evaluate the stability of four proposed harbor-side re-
habilitation designs, one each for the west breakwater at
*A table of factors for converting U. S. customary units ofmeasurement to metric (SI) units is presented on page 3.
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sta* 21+25 and sta 18+50 and the east breakwater atsta 26+10 and sta 23+35.
b. Evaluate the stability of the proposed sea-side rehabil-itation design for the west breakwater at sta 18+50.
c. If any of the proposed designs prove unstable for theselected test waves and still-water level conditions, testalternative designs until a stable section is found.
d. Evaluate the stability of the existing tribar protectionon the sea-side slope of the west breakwater atsta 21+25.
f
* For convenience, symbols and unusual abbreviations are listed anddefined in the Notation (Appendix A).
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PART II: THE MODEL
Design of Model
3. Tests were conducted at undistorted linear scales of 1:33,
1:36, and 1:40, model to prototype. Scale selections were based on the
size of model armor units available relative to the size of prototype
armor units existing on and/or proposed to be added to the prototype
breakwaters, elimination of stability scale effects,* and capabilities
of the available wave tank. Based on Froude's model law^- and the
linear scales of 1:33, 1:36, and 1:40, the following model-to-prototype
relations were derived. Dimensions are in terms of length (L) and
time (T).
Model-Prototype Scale Relationsfor Model Scales of
Characteristic Dimension 1:33 1:36 1:40
Length L La = 1:33 1:36 1:40
Area L2 A = L2 = 1:1,089 1:1,296 1:1,600a a
Volume L3 V = L3 = 1:35,937 1:46,656 1:64,000a a
Time T T = L1/ 2 =1:5.7 1:6 1:6.3a a
4. The specific weight of water used in the model was assumed to
be 62.4 pcf and that of seawater is 64.0 pcf. Specific weights of model
breakwater construction materials were not identical to their prototype
counterparts. These variables were related using the following trans-
ference equation:
(W) (y) 3m (S Ir r L(rp (¥)p -LPI m
* R. Y. Hudson. 1975 (Jun). "Reliability of Rubble-Mound BreakwaterStability Models," Miscellaneous Paper H-75-5, U. S. Army EngineerWaterways Experiment Station, CE, Vicksburg, Miss.
** J. C. Stevens, et al. 1942. "Hydraulic Models," Manual ofEngineering Practice No. 25, American Society of Civil Engineers,New York.
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where
subscripts m and p = model and prototype quantities, respectively
W = weight of an individual armor unit or stone,r lb
Yr = specific weight of an individual armor unitor stone, pcf
Lm/Lp = linear scale of the model
S = specific gravity of an individual armor unitr or stone relative to the water in which the
breakwater was constructed, i.e., Sr = Yr/'g
yw = the specific weight of water, pcf
Test Facilities and Equipment
5. All tests were conducted in a 100-ft-long, 5-ft-wide, and
3-ft-deep flume that is located within an L-shaped wave basin, which has
overall dimensions of 250 ft long, 50 and 80 ft wide at the top and
bottom of the L, respectively, and 4.5 ft deep (Figure 2). The test
facility is equipped with a flap-type wave generator capable of produc-
ing monochromatic waves of various periods and heights.
Model Construction and Testing Procedures
Modeling local bathvmetry
6. A iV-on-luOH slope was selected as representative of the pro-
totype bathymetry seaward of the east breakwater at sta 23+35. The
bathymetry seaward of the other three test sections was -epresented by a
IV-on-27H slope. A 35-ft (model) length of iV-on-27H slope was preceded
by 43 ft (model) of iV-on-lOOH slope in the test flume as shown in
Figure 2.
Flume calibration
7. Following molding of the local bathymetry and prior to instal-
lation of the first test section, the test flume was calibrated for the
wave periods and water depths selected for this study. Test waves of the
required characteristics were generated by varying the frequency and
amplitude of the wave generator paddle. Changes in water-surface
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250
A = 75' OF VIEWING WINDOW A
WA VEGENERA TOR
20D TEST AREAKAHULULI STABILITY TESTS
VERTICALGUIDEVANES
,-ROCK
WA VE
PLAN ABSORBERI
33.3 700 2
SECTION A-A
Figure 2. Tes: flume geometry
elevations as a function of time were measured by electrical wave-height
gages and recorded on chart paper by an electrically operated oscillo-
graph. Wave gages were located along the test slopes where the sea-side
toes of the test sections would be located. Figure 3 shows the wave
gage locations on the 1V-on-27H and 1V-on-100H slopes for the various
test sections.
Methods of constructing test sections
8. Existing conditions of the prototype breakwater sections and
characteristics of the proposed rehabilitation work were defined by
means of acrial photographs and/or line drawings furnished the U. S.
Army Engineer Waterways Experiment Station (WES) by POD. In cases where
the proposed rehabilitation proved unstable, modifications to the new
construction were made based on model observation and discussions be-
tween WES and POD personnel.
9. Model breakwater sections were constructed to reproduce, as
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closely as possible, the existing breakwater conditions and the results
of the usual methods of constructing prototype structures. Core mate-
rial was dumped by bucket or shovel into the flume and was smoothed to
grade and compacted with hand trowels to simulate natural consolidation
resulting from wave action during construction of the prototype break-
water. The old cover-layer stone, 16,000 lb on all test sections, was
then added by shovel and smoothed to grade by hand or with trowels but
was not compacted. Concrete armor units used in the cover layer, or
layers, were placed either in a random manner, i.e., placed in such a
way that no intentional interlocking of the units was obtained, or with
uniform placement where very close spacing and some intentional inter-
locking of the units was achieved. (Uniform placement should not be
confused with pattern placement where each unit is laid down with a
predetermined orientation.) Some "special" and "extra-special" place-
ment of the toe dolosse was used. These toe construction techniques
are described and illustrated in latter portions of this report.
10. Where crown protection was provided by cast-in-place concrete
caps and/or concrete ribs, it was assumed that they are or will be
stable in the prototype; therefore, it was not necessary that they be
dynamically similar to the prototype. The model ribs and caps, con-
structed of Plexiglas, were geometrically similar to their prototype
counterparts and were held in place in the model, thus ensuring proper
transmission, reflection, and dissipation of wave energy and the assumed
stability of the structures.
Selection of test conditions
11. Based on anticipated prototype conditions and available
prototype data, POD decided that the stability tests should use wave
periods of 14, 16, and 18 sec. All test sections were tested with a
still-water level (swl) of +4.0 ft mllw and the west breakwater sections
were also tested for a low water condition of -1.0 ft mllw. This low
swl was used to evaluate stability of the existing and proposed lower,
sea-side slopes of the west breakwater at sta 21+25 and sta 18+50,
respectively.
12. When the first test section for each of the four proposed
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designs was installed in the flume, it was exposed to a range of wave
heights at each of the selected wave periods and swl's. Model observa-
tions for all four initial test sections indicated that wave attack with
the 14-sec wave period was significantly less severe than either the 16-
or 18-sec periods. The wave forms for the 16- and 18-sec wave periods
appeared to be similar with the 18-sec period being slightly more severe.
Based on these observations, the 16- and 18-sec wave periods were
selected for all the full length stability tests.
13. Except for the 16-sec period on the west breakwater at
sta 21+25, the depth-limited breaking waves were found to be the most
severe condition with respect to stability of both the sea- and harbor-
side slopes for all test sections. On the west breakwater at sta 21+25,
a wave height slightly less than the depth-limited breaking wave height
for the 16-sec wave period was found to be more severe for the harbor-
side slope. Based on these observations and those described in para-
graphs 11 and 12, the following hydrographs were selected for testing
the various breakwater sections: (a) Hydrograph A, Plate I and Table 1,
for the west breakwater at sta 21+25, (b) Hydrograph B, Plate 2 and
Table 2 for the west breakwater at sta 18+50, (c) Hydrograph C, Plate 3
and Table 3 for the east breakwater at sta 26+10, and (d) Hydrograph D,
Plate 4 and Table 4 for the east breakwater at sta 23+35.
14. All the waves included in Hydrographs A, B, and C are best
classified as depth-limited plunging breakers except for the shakedown
waves which are used to simulate wave attack during construction. The
test waves of Hydrograph D were depth-limited spilling breakers which
appear to be a less severe form of breaking waves. These differences
in wave forms for the same prototype wave periods were a result of the
different bathymetry seaward of the test sections. The steeper IV-on-
27H slope was used with Hydrographs A, B, and C and produced the more
severe plunging breakers while the IV-on-lOOH slope was used with Hydro-
graph D and produced the less severe spilling breakers.
Model operation
15. Once test conditions for the breakwater section were experi-
mentally determined, the breakwater cover layers were rebuilt. Before
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test photographs were taken, the flume was flooded to the appropriate
depth; and the -structure was exposed to the shakedown and test waveconditions. Prototype test time was accumulated in 30 sec (model time)
cycles, i.e., the wave generator was started, run for 30 sec, and then
stopped. This procedure eliminated contamination of generated waves by
reflections from the structure that could be rereflected from the wave
generator. After each 30-sec cycle, sufficient time was provided for
the test basin to still out before the next cycle was run. During
stilling time between cycles, detailed model observations of the struc-
ture's response to the previous cycle of test waves were recorded by the
model operator. These observations included any movement occurring on
the structure and a general statement of the condition of the structure
at that point in the test. At the conclusion of the test, the flume was
drained and the After-test condition of the structure was summarized
in the test notes and documented with photographs. For most of the
test sections, the cover layers were then rebuilt and the test was re-
peated. The purpose of the repeat test was to determine if there were
any uncontrolled variations in model construction technique that af-
fected stability of the structure. In all cases the repeat tests showed
very similar results.
Methods of reporting model
observations and test results
16. The following list of adjectives, in order of increasing
severity, was used for recording model observations and reporting test
results for each test section: (1) slight, (2), minor, (3) moderate,
(4) significant, (5) major, and (6) extensive. Slight and minor were
used to describe acceptable results, moderate described borderline
acceptability, while significant to extensive described unacceptable
conditions of increasing severity. Use of these adjectives allows for
some quantification of the severity and/or amount of rocking in place,
onslope displacement, offslope displacement, and resulting damage
accrued by the breakwater's primary cover-layer units. By using the
descriptive adjectives and the before- and after-test photographs,
comparisons can be made between alternative test sections.
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PART III: DESCRIPTION OF EXISTING SECTIONS, TESTPLANS, AND TEST RESULTS
West Breakwater at Sta 21+25
17. The existing section, Plate 5, consists of 4,000- to 8,000-lb
core stone overlaid by one layer of random-placed 16,000-lb stone. Two
layers of random-placed, 38,000-lb tribars cover the sea-side slope from
the -25.0 ft mllw toe to the +16.3 ft mllw crown. The 19.5-ft-wide
crown is protected by cast-in-place concrete ribs. The individual ribs
are 27 ft long, 4 ft high (average), and 3 ft wide. The ribs make a
46-deg angle with respect to the longitudinal axis of the breakwater and
are spaced on 6-ft centers.
18. Plan 1, Plate 6 and Photos 1-3, consisted of existing condi-
tions, except for one minor modification, and incorporated the proposed
harbor-side rehabilitation design. The existing 38,000-lb tribars were
represented in the model as 38,220-lb tribars. This minor difference in
weight was due to the available model armor unit sizes and the selected
scale necessary to model the 13,600- to 18,400-lb harbor-side armor
stone proposed for the rehabilitation work. The harbor-side armor stone
was randomly placed on a 1V-on-2H slope from the 16,000-lb stone apron
to an elevation of +15.3 ft mllw. During Hydrograph A, Plan 1 accrued
no damage to the sea-side tribars and significant damage to the harbor-
side, 13,600- to 18,400-lb armor stone. During Steps 3-5, 21 armor
stones were displaced from the 1V-on-2H slope. The displacement was
caused by a combination of wave energy transmitted through and over-
topping the structure. Minor rocking of one or two of the sea-side
tribars was noted throughout the test, but no displacement occurred. By
the end of Step 5, all damage had ceased and the structure sustained no
further damage during the remainder of Hydrograph A. Photos 4-6 show
the condition of Plan 1 after its first testing with Hydrograph A.
Plan 1 was rebuilt and exposed to Hydrograph A once again. Results of
the second test were very similar to the first, with 15 armor stones
displaced from the lV-on-2H, harbor-side slope and minor rocking of 2 or
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3 sea-side tribars throughout the test. All damage had stabilized by
the end of Step 5 and the after-test condition of Plan 1 is shown in
Photos 7-9. Both testings of Plan 1 showed more damage to the harbor-
side armor stone than would be acceptable for a no-damage design.
19. In an effort to stabilize the 13,600- to 18,400-lb armor
stone, the harbor-side slope was flattened to IV on 2.5H, Plan 1-1,
Plate 7. During testing of Plan 1, it was noted that Steps 3 and 5
produced the most damaging conditions on the harbor-side armor stone
stability. Based on this observation, it was decided that Plan 1-1
would only be exposed to the shakedown and Steps 1, 3, and 5 of Hydro-
graph A. After exposure to these conditions, damage to Plan 1-1 was
similar to that for Plan 1.
20. Due to the limited availability of stones larger than
16,000 lb and the probability that the 16,000-lb stone would be more
expensive than originally expected, POD requested that WES pursue a
series of tests to determine the sizes of dolosse and tribars that were
needed for stability when placed on the IV-on-2H harbor-side slope and
exposed to the wave and swl conditions of Hydrograph A.
21. Plan IA, Plate 8 and Photos 10-12, was identical to Plan 1,
except for the armor and fill material placed on the harbor side of the
breakwater. Two layers of 3,740-lb dolosse were placed on a iV-on-2H
slope over the 800-lb stone used as fill between the dolosse and exist-
ing 16,000-lb stone. Random dolos placement was used on both the toe
and the slope. The dolosse showed no instability during Steps 1 and 2,
but Steps 3-5 caused major failure. Steps 6 and 7 caused no additional
damage. As with Plans 1 and 1-1, the existing sea-side tribars showed
no instability for Plan IA. Photo 13 shows the condition of the dolosse
at the end of Step 3 and Photos 14-16 show Plan IA at the end of the
test. As shown in Photo 16, a major portion of the dolosse were dis-
placed from the IV-on-2H slope resulting in a large area of exposed
16,000-lb stone. The dolos displacement had not subsided at the end of
Step 5, and more extensive dolos damage would most likely have occurred
if the duration of Step 5 were extended.
22. The dolos armor size was increased to 6,765-lb for Plan 1B,
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Plate 8 and Photos 17 and 18, in an effort to find a stable dolos design.
Using random placement, two layers of dolosse were placed on a IV-on-2H
slope over the 1,350-lb fill material. Plan lB was exposed to Steps 1-5
of Hydrograph A. Less dolos displacement occurred for Plan IB than for
Plan IA; however, the displacement was still significant and was much
more than would be acceptable for a no-damage design. All the dolos
damage observed occurred during Steps 3-5 and the damage had not sub-
sided at the end of Step 5. A total of 21 dolosse had been displaced
completely off the lV-on-2H slope and there were several areas where
only one layer of dolosse remained on the slope. Minor rocking of two
to three tribars was noted on the sea-side slope, but no displacement
was observed. Photos 19-21 show the condition of Plan IB at the end of
the test.
23. Plan IB-l, Plate 8, was identical to Plan IB except for the
placement of the dolosse along the toe of the harbor-side IV-on-2H slope.
Plan IB used totally random placement, whereas a "special placement" was
used on the toe of Plan IB-I. Photo 22 shows a comparison of random and
special placement of toe dolos units. (In an effort to expedite deter-
mination of acceptable dolos and tribar designs for the west breakwater
at sta 21+25, only Steps 1, 3, and 5 of Hydrograph A were selected for
testing the stability of various designs and only one testing of each
design was conducted. Once acceptable designs were found, POD selected
one dolos and one tribar design and a repeat test was conducted for
these plans using the full duration and all the test conditions of
Hydrograph A.) One dolos was displaced during Step 3 and 18 more were
displaced during Step 5 of Hydrograph A. All displacement had subsided
by the conclusion of Step 5 and the after-test condition of the section
is shown in Photos 23 and 24. Although major failure did not occur, the
dolos displacement was significant enough for the design to be con-
sidered unacceptable.
24. For Plan 1C, Plate 9, the harbor-side dolos size was in-
creased to 9,670 lb and no underlayer was used between the dolosse and
the 16,000-lb rock. Special placement was used on the dolos toe and the
remainder of the slope was constructed using two layers of randomly
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placed dolosse. At the conclusion of the test, two dolosse had been
displaced off the slope and out onto the 16,000-lb rock apron. All
displacement had stopped, but a significant amount of rocking in place
of dolosse was still occurring. Photos 25 and 26 show Plan IC after
testing.
25. Plan 1D, Plate 9, was constructed identical to Plan IC, but
the dolos size was increased to 15,325 lb. During Steps 3 and 5 of
Hydrograph A, three areas of the specially placed toe were damaged and
this resulted in displacement of 14 dolosse. The displacement had
stopped at the end of the test, but the amount of damage was greater
than that allowable for an acceptable design. Photos 27 and 28 show
Plan 1D after testing.
26. Plan 1D-1, Plate 9, was identical to Plan ID except for the"extra special" placement used on the dolos toe of Plan ID-I. This
extra special toe placement is shown in Photo 29. In this placement,
extra care is taken to ensure that at least one, and most of the time
two, dolosse are placed so as to hold the outermost toe dolosse in
place. In using this type of placement, some areas of the toe were
built using three layers of dolosse. During Step 5 of Hydrograph A,
two dolosse were displaced and all damage had stabilized by the end of
the test. Only very minor rocking in place of one or two additional
dolouse was noted during the test. Photos 30 and 31 show the conditions
of Plan 1D-1 after testing.
27. Tests were conducted for Plan ID-2, Plate 10, to see if the
toe dolosse placed in a trench 4sing special placement would have equal
or greater stability than the same size dolosse that were not trenched,
but were placed using extra special toe placement. Except fer the con-
st~uction technique used on the harbor-side dolos toe, Plan ID-2 was
identical to Plans 1D and 1D-1. A trench approximately 8 to 10 ft wide
was formed by removing the one layer of 16,000-lb stone. The 15,325-lb
dolosse were placed along the toe using special placement, while the
onslope dolosse were randomly placed. Four dolosse were displaced off
the slope during Step 5 of Hydrograph A, but no movement occurrel along
the specially placed trenched toe. All damage had stabilized before the
17
-
end of the test and Photos 32 and 33 show the section after testing.
28. Plan 1E, Plate 11, was tested to determine if larger dolosse
would be stable without the toe of the slope being trenched. Two layers
of 20,945-lb dolosse were placed on the harbor-side slope using extra
special placement along the toe and random placement on the remainder
of the slope. One dolos was displaced during Step 5 of Hydrograph A.
This dolos was originally positioned at the top of the slope next to
Lhe concrete rib and a large portion of the dolos projected up higher
than the +16.3-ft mllw crown elevation. This was the only movement
observed during testing of Plan 1E. Photos 34 and 35 show Plan 1E
after testing.
29. Having found both low- and no-damage dolos designs for the
harbor-side slope (based on one testing only), tests were initiated to
find a tribar armor unit size that would be stable on the harbor-side
slope when exposed to Steps 1, 3, and 5 of Hydrograph A. Plan IF,
Plate 12, was identical to all previous plans tested, except for the
iV-on-2H harbor-side slope design. One layer of uniform-placed,
13,065-lb tribars was used to protect the harbor-side slope. Stones
with an average weight of 1,307 lb were used as fill between the tribars
and the 16,000-lb stone. Major offslope displacement of the harbor-side
tribars occurred during Steps 3 and 5. A total of 34 tribars had been
displaced and the damage had not subsided when the test ended. The
condition of Plan IF at the end of the test is shown in Photos 36 and 37.
30. Plan IF was rebuilt; however, the first row of tribar units
was placed along the toe of the harbor-side slope with the base of all
three legs resting on an approximately horizontal plane. The next row
of tribars placed started up the iV-on-2H slope. Plan IF accrued as
much or possibly more damage during the second testing than during the
initial test. Approximately one-third of the tribars had been displaced
when the test ended. Damage had not stabilized but the harbor-side
slope had failed (Photos 38 and 39). The tribar damage was initiated by
displacement of several of the tribars along the toe. Once these units
were displaced, the upper slope unraveled at a very fast rate.
31. In an effort to stabilize the toe and thus achieve a stable
18
-
tribar design for the harbor-side slope, tests were initiated for
Plan 1F-I (Plate 13). A trench, approximately 8 to 10 ft wide, was
formed by removing the one layer of 16,000-lb stone. The seaward side
of the trench had a slope of IV on 2H. This was accomplished by partial
removal of 16,000-lb stone and backfilling the voids in this area with
the same size, 1,307-lb rock that was used as a fill beneath the tribars
on the upper portion of the slope. Where it was possible, the toe row
of 13,065-lb tribars was placed in the trench with all three legs of the
tribar unit resting on the bottom of the trench. Above the toe trench,
one layer of tribars was uniformly placed on the 1V-on-2H slope. During
Step 5 of Hydrograph A, one of the toe tribar units flipped over on its
side and the unit just above it was displaced out onto the 16,000-lb
rock apron. No other movement was observed during the test and all
damage had stabilized well before the end of the test. Photos 40 and
41 show Plan 1F-1 after testing.
32. Plan 1G, Plate 12, used the identical construction as the
second testing of Plan IF, paragraph 30. On Plan 1G, the harbor-side
tribar size was increased to 20,000 lb and 2,000-lb stones were used as
fill between the tribars and 16,000-lb stone. The 20,000-lb tribars
accrued significant damage during Step 5 of Hydrograph A. The damage
started with displacement of several toe units which led to instability
of the upper slope tribars and ultimate failure of the harbor-side slope.
The damage did not stabilize and is shown in after-test Photos 42 and 43.
Damage exceeded an acceptable amount.
33. The toe of the 20,000-lb tribars was trenched for Plan 1G-l,
Plate 14, in an attempt to stabilize the toe and achieve a no-damage
tribar design for the harbor-side slope. A 1V-on-2H slope was con-
structed in the 12-ft-wide trench and a portion of the upper slope by
using a 2,000-lb rock fill. One layer of 20,000-lb tribars was placed,
using uniform placement, from the toe to the crown of the harbor-side
slope. The 20,000-lb tribars sustained no damage during testing and
there was no evidence of any instability at the end of the test.
Photos 44 and 45 show Plan 1G-1 after testing.
34. In the event that toe trenching cannot be achieved in the
19
-
prototype, tests were conducted for Plan IH (Plate 15). Plan 1H was
identical to Plan IG, described in paragraph 32, except for the
20,000-lb tribar toe units which were replaced with 28,250-lb tribars.
During Step 5 of Hydrograph A, four of the 28,250-lb tribar units were
displaced and this caused some downslope slippage of the 20,000-lb
tribars. The damage had not stabilized but was progressing at a very
slow rate when the test was stopped. Photos 46 and 47 show Plan 1H
after testing.
35. Plan 11, Plate lb, was identical to Plan 111 except for the
toe row of tribars on the harbor-side slope. The 28,250-lb tribars used
in Plan 11 were replaced by 38,220-lb tribars for Plan II. Two of the
toe tribars were displaced during Step 5 of Hydrograph A, but no other
movement of tribar units was observed. All damage had stopped well
before the end of the test and Photos 48 and 49 show Plan II after
testing.
36. POD stated that the toe trenching could be accomplished in
the prototype and selected Plans 1F-l and ID-2, Plates 13 and 10,
respectively, for repeat testing using all seven steps of Hydrograph A.
Plan IF-I was reconstructed, Photos 50 and 51, and exposed to the wave
and swl conditions of Hydrograph A. No displacement of the 13,065-lb
tribars occurred. Photos 52 and 53 show Plan lF-i after testing.
37. Plan 1D-2 was reconstructed in the test flume, Photos 54 and
55, and exposed to Hydrograph A. Exposure to the shakedown and Steps 1
and 2 caused no dolos movement on the harbor side of the breakwater.
During the early portion of Step 3, one dolos was displaced from the
upper slope onto the 16,000-lb rock apron and one dolos from the upper
slope was displaced on, but not off of, the IV-on-2H slope. No other
movement occurred until the first part of Step 5. At this time, several
dolosse near the center of the section and on the upper slope turned
over but were not displaced from the dolos area. Approximately halfway
through Step 5, one additional dolos turned over in place and the dolos
that was displaced onslope during Step 3 was moved off the slope and out
onto the rt'k apron. All movement stopped well before the end of Step 5,
and no additional movement was noted during exposure to the remainder of
20
-
Hydrograph A. Photos 56 and 57 show the condition of Plan 1D-2 after
this test.
38. During the first tests of the west breakwater at sta 21+25,
the existing sea-side tribars proved to be stable for the test condi-
tions of Hydrograph A. Therefore, the sea-side slope was not rebuilt
between subsequent tests for the last 12 testings of various harbor-side
designs. Minor rocking of one or two tribars was noted during a few of
the earlier tests, but no displacement of tribars or deterioration of
the sea-side slope was noted. Thus, the after-testing, sea-side view
of Plan ID-2, Photo 58, shows the 38,220-lb tribars after a cumulative
exposure to approximately 4 hr of Step 1, 0.5 hr of Step 2, 12 hr of
Step 3, 1 hr of Step 4, 12 hr of Step 5, 0.5 hr of Step 6, and 0.5 hr
of Step 7 of Hydrograph A.
West Breakwater at Sta 18+50
39. The existing section, Plate 16, consists of 4,000- to
8,000-lb core stone overlaid with one layer of random-placed, 16,000-lb
stone. The 16,000-lb stone extends from the -25.0 ft mllw sea-side toe
to a crown elevation of +12.1 ft mllw and continues down the harbor side
to the toe elevation of -17.0 ft mllw. Seaward of sta 18+50, the sea
floor rises to a shallower depth of approximately -20.0 ft mllw. There-
fore, a depth-limited breaking wave for the water depth existing at the
sea-side toe of sta 18+50 would break seaward of the breakwater and the
maximum breaking wave that could reach the breakwater at sta 18+50 is
controlled by the -20.0 ft mllw elevation seaward of the breakwater.
Based on this, the decision was made to use a -20.0 ft mllw sea-side toe
elevation in the model with a iV-on-27H slope extending seaward from the
toe of the structure.
40. A concrete wall extends up to an elevation of +13.0 ft mllw
on the harbor side of the crown. Portions of the wall have been lost
during severe storms and the remaining wall is not structurally sound.
The wall does reduce overtopping wave energy, but due to its structural
weakness and the probability of destruction during future storms, it was
21
. . . . . . . . . . . . i f i t l t I . .. . . I I II I III
-
assumed nonexistent for purposes of the model study.
41. Plan 2, Plate 17 and Photos 59-61, was constructed to a crown
elevation of +12.1 ft mllw. One layer of random-placed, 16,000-lb stone
covered the 4,000- to 8,000-lb core material. The proposed rehabilita-
tion construction consisted of one layer of uniform-placed triba[s on
1V-on-2H slopes on the sea side and harbor side of the breakwater. The
toes of the 21,758-Ib, sea-side tribars and the 10,064-lb, harbor-side
tribars were trenched into the existing 16,000-lb stone. Stone averaging
2,176 lb was used as fill between the sea-side tribars and the 16,000-lb
stone. During Step 2 of Hydrograph B, several of the 16,000-lb stone
were displaced from the sea-side toe up onto the lower, sea-side tribars;
but this did not result in any instability of the tribar toe area.
Steps 3 and 4 caused a moderate amount of displacement and reorientation
of the tribars and armor stone along the breakwater crown. Six of the
sea-side tribar units, four along the crown and two on the lower slope,
were turned up on their sides and one additional sea-side tribar unit
was displaced over the crown and down to the toe of the harbor-side
tribars. Displacement of 16,000-lb stone on the breakwater crown re-
sulted in spot lowerings of 3 to 4 ft. None of the harbor-side tribars
were displaced from their original location, but a noticeable bulge
occurred in one area of the upper slope. This occurred due to a com-
bination of overtopping and transmitted wave energy and the impact of
the 16,000-lb crown stone against the tribars along the top of the
harbor-side slope. A few sea-side tribar units rocked in place through-
out testing at the +4.0 ft mllw swl, but all damage had subsided well
before the end of Step 4 and no additional displacement occurred during
the remainder of Hydrograph B. Photos 62-64 show the condition of
Plan 2 at the conclusion of the first test. Plan 2 was rebuilt and once
again exposed to Hydrograph B. A moderate amount of reorientation and
displacement occurred on the upper sea- and harbor-side slopes. None of
the sea-side tribar units were displaced during this test, but three
harbor-side tribar units were displaced down to the 16,000-lb stone on
the harbor-side toe. Displacement of the 16,000-lb crown stone once
again resulted in spot lowerings of 3 to 4 ft along the breakwater crown.
22
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All damage had stabilized during Step 4 of Hydrograph B and the condi-
tion of the structure at the end of the test is shown in Photos 65-67.
42. A concrete rib cap was added to the crown of the breakwater
to provide a buttress for the sea-side tribars, to help stabilize the
crown stone, and to reduce the amount of overtopping wave energy reach-
ing the harbor-side tribar units. To expedite the tests, the rib cap
used was the same one as had been used for all of the tests previously
reported for the west breakwater at sta 21+25. Due to the difference in
model scales, 1:36 for sta 21+25 and 1:33 for sta 18+50, the rib cap
represented a slightly smaller prototype size for the tests at sta 18+50.
The individual ribs represented were 24.8 ft long, 3.7 ft high, and
2.8 ft wide. Other than the concrete rib cap and the extension of the
sea-side tribars up to the +15.8 ft mllw crown elevation, Plan 2A
(Plate 18 and Photos 68-70) was identical to Plan 2. Plan 2A was ex-
posed to the wave and swl conditions of Hydrograph B. Compared with
Plan 2, there was a noticeable decrease in the amount of overtopping
wave energy observed in Plan 2A and only minor damage was accrued by
the breakwater. Two or three 16,000-lb stones were displaced up onto
the toe of the sea-side tribars and two tribars were displaced from one
area of the harbor-side slope. All damage had stopped well before the
end of Step 4, and Photos 71-73 show the condition of the breakwater at
the end of the test. Plan 2A was rebuilt and once again exposed to
Hydrograph B. One armor stone was displaced from the sea-side toe area
up onto the sea-side tribars during Step 2. This was the only movement
observed during the test and Photos 74-76 show that Plan 2A was in very
good condition at the end of the test.
East Breakwater at Sta 26+10
43. The existing section, Plate 19, consists of 4,000- to
8,000-lb core stone overlaid by one layer of random-placed 16,000-lb
stone. The sea-side slope is covered by two layers of random-placed,
70,000-lb tribars and the crown is covered by concrete ribs that overlay
a concrete cap. The individual ribs are 20.0 ft long, 3.0 ft wide, and
23
-
vary in height from 4.0 ft on the sea side to 10.0 ft on the harbor
side. The ribs are spaced on 6.0-ft centers, are oriented at a 90-deg
angle to the longitudinal axis of the breakwater, and extend up to an
elevation of +16.6 ft mllw. The elevations of the sea- and harbor-side
toes are -40.0 and -28.3 ft mllw, respectively, Just seaward of the
breakwater toe at sta 26+10 the sea floor rises to an elevation of
-38.0 ft mllw.
44. Plan 3, Plate 20 and Photos 77-79, was constructed in the
model and reproduced the existing conditions except for the following
modifications: (a) the 70,000-lb sea-side tribars were represented as
70,800 lb due to size of available model units and the 1:40-scale
selected to reproduce the size of tribar units tested on the harbor-
side slope, and (b) the -38.0 ft mllw elevation was selected as the
controlling depth for the maximum breaking wave height that could reach
the breakwater; therefore, the model breakwater toe was located at this
elevation. The harbor-side rehabilitation work consisted of one layer
of 17,920-lb tribars, uniformly placed on a lV-on-2H slope. The toe of
the tribars was trenched into the 16,000-lb stone and the tribar protec-
tion extended up to +12.6 ft mllw. The area between the tribars and
16,000-lb stone was filled with 1,790-lb stone. Plan 3 accrued very
slight damage during its first exposure to the wave conditions of Hydro-
graph C. The existing sea-side tribars showed some slight reorientation
and two units were displaced onslope. The only other movement observed
was some displacement of 16,000-lb stone on the harbor-side toe and some
slight rocking in place of two or three tribar units on the upper
harbor-side slope. All damage had stopped well before the end of Hydro-
graph C and Photos 80-82 show that Plan 3 was in excellent condition at
the end of the first test. The harbor-side rehabilitation area was re-
built and the test conditions of Hydrograph C were repeated. The test
results were identical to the first test, except for the displacement of
one harbor-side tribar unit that occurred during Step 1. All damage
stabilized well before the end of the test. Photos 83-85 show Plan 3
after testing.
24
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East Breakwater at Sta 23+35
45. The existing breakwater section, Plate 21, consists of 4,000-
to 8,000-lb core stone overlaid by one layer of random-placed 16,000-lb
stone. The sea-side slope is covered from the -45.0 ft mllw toe eleva-
tion to the +14.8 ft mllw crown with two layers of random-placed
60,000-lb dolosse. Portions of an old access road still exist on the
breakwater crown; the road is contained by concrete walls on the sea-
and harbor-sides of the crown. The gravel fill and asphalt cap between
the walls has accrued significant damage, and stability of the walls is
very questionable. Therefore (for purposes of the model study), the
walls were considered nonexistent and the crown elevation of the first
test sections was set at +11.5 ft mllw which is the existing elevation
of the 16,000-lb stone at sta 23+35.
46. Plan 4, Plate 22 and Photos 86-88, was constructed in the
model to reproduce conditions described in the previous paragraph.
Due to the 1:40 scale necessary to reproduce the proposed harbor-side
tribar size, the nearest available size of model dolos units rerresented
58,500 lb instead of the desired 60,000 lb. The harbor-side rehabili-
tation construction was composed of one layer of 17,920-lb tribars
uniformly placed on a iV-ou-2H slope. The tribar toe was trenched into
the 16,000-lb stone and the units extended up to the +11.5 ft mllw
crown elevation. Stone weighing an average of 1,790 lb was used as
fill between the tribars and 16,000-lb stone. During the shakedown
and both steps of Hydrograph D, significant damage was accrued by the
breakwater crown area. A large amount of reoriention, rocking in place,
and displacement of the 58,500-lb dolosse occurred along the upper sea-
side slope. Four dolosse were displaced over the crown and down onto
the harbor-side slope. One additional dolos was locked into the
16,000-lb stone on the crown. The 16,000-lb crown stones were displaced
both toward the back of the crown and completely over the crown and down
the harbor side of the breakwater, resulting in up to 10-ft reductions
in crown elevation at isolated locations. One harbor-side tribar was
displaced from the upper slope down to the harbor-side stone apron. No
25
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other tribar displacement was observed; however, a significant number of
crown stones were pushed back and lodged against the top harbor-side
tribars. The impact between the armor stone and tribars would most
likely result in more significant prototype damage due to possible
breakage of armor units. The rate of displacement and damage to the
breakwater crown had slowed but had not subsided at the end of the
hydrograph. Photos 89-91 show that damage sustained by the breakwater
far exceeded an acceptable amount for a no-damage design.
47. A concrete rib cap was added to the section to provide but-
tressing for the dolosse and to help stabilize the armor-stone crown.
The rib cap used in Plan 3A was modified to represent a constant 4-ft
height. Plan 4 was rebuilt and with the rib cap installed was referred
to as Plan 4A, Plate 22 and Photos 92-94. During exposure to Hydro-
graph D there was some minor in-place rocking and reorientation of the
dolos and tribar units along the edges of the breakwater crown. In a
repeat test, the harbor-side armor layer was rebuilt and the section was
once again subjected to the wave conditions of Hydrograph D. Results of
the repeat test were very similiar to results of the original test.
During both tests, a significant reduction in overtopping wave energy was
observed for Plan 4A relative to Plan 4. Photos 95-97 and 98-100 show
the conditions of Plan 4A after the first and second tests, respectively.
26
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PART IV: CONCLUSIONS
48. Based on the tests and results reported herein, it is con-
cluded that:
a. For the west breakwater at sta 21+25 exposed to the waveand swl conditions of Hydrograph A, Plate 1 and Table 1:
(1) The existing 38,220-lb (19 ton) tribars are an ade-quate design for the sea-side slope.
(2) The 1V-on-2H harbor-side slopes of Plans 1, IA, 1B,1B-l, IC, iD, IF, 1G, and 1H and the 1V-on-2.5Hharbor-side slope of Plan 1-1 are not adequatedesigns.
(3) Plans ID-l, ID-2, IF-l, and 1I are adequate iV-on-2Hharbor-side slope designs if some potential minordamage and displacement of armor units areacceptable.
(4) Plans 1G-1 and 1E appear to be unconditionallyacceptable designs of IV-on-2H harbor-side sloperehabilitation. The harbor-side rehabilitationportions of these plans consisted of 10-ton tribarsand 10.5-ton dolosse, respectively. The tribarswere keyed into the existing 8-ton stone layer witha trench. For the dolosse, extra special placementof the toe units was necessary.
b. The proposed rehabilitation designs for the sea- andharbor-side slopes of Plan 2 for the west breakwater atsta 18+50 are not adequate for the wave and swl condi-tions of Hydrograph B, Plate 2 and Table 2. With theaddition of a concrete rib cap (Plan 2A), the same armorand slope designs tested for Plan 2 proved to be adequate.The sea-side slope rehabilitation consisted of 11-tontribars, and 5-ton tribars were used on the harbor-sideslope. Both slopes were IV on 2H and were keyed into theexisting 8-ton stone layer with a trench.
c. The existing sea-side slope (35-ton tribars) and theproposed harbor-side rehabilitation design for Plan 3for the east breakwater at sta 26+10 proved to be ade-quate for the test conditions of Hydrograph C, Plate 3and Table 3. The harbor-side rehabilitation consisted of9-ton tribars on a IV-on-2H slope layered into the exist-ing 8-ton stone layer with a trench.
d. The crown areas of the proposed harbor-side design andexisting sea-side design of Plan 4 for the east break-water at sta 23+35 were not adequate for the wave and swl
27
-
conditions of Hydrograph D, Plate 4 and Table 4. Plan 4A,identical to Plan 4 except for the addition of a concreterib cap, proved acceptable when exposed to the identicaltest conditions. The harbor-side rehabilitation con-sisted of 9-ton tribars on a IV-on-2H slope keyed intothe existing 8-ton stone layer with a trench.
28
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PART V: DISCUSSION
49. It is imperative that the trenching and/or special placements
described in this report for the toe units be strictly followed during
construction. The stability of the various acceptable designs is highly
dependent upon achieving the toe placement recommended. Failure to
follow the guidance provided regarding toe design will probably result
in significant damage to the structure.
50. Model observations indicated that during rehabilitation con-
struction of the harbor-side slopes, care should be taken to maintain
as low a profile as possible along the crown of the slope, i.e.,
regardless of the type (dolos or tribar) of armor unit being placed,
the crown units should not project above the concrete ribs more than
necessary. Model tests indicated that (for the harbor-side slopes),
it was better to leave a small gap between the concrete ribs and the
top armor units than to fit a unit in this space if a large portion of
the unit had to project above the crown elevation of structure.
V
29
,..-
-
Table 1
Hydrograph A
Test Wave Prototypeswl Period Height Duration
Step ft mllw sec ft hr Wave Type
-1.0 16.0 i.0 0.25 Shakedown
1 -1.0 16.0 19.5 0.25 Worst breaking(Sea-side armor)
2 -1.0 18.0 21.0 0.25 Worst breaking(Sea-side armor)
3 +4.0 16.0 24.5 1.0 Worst breaking(Harbor-side armor)
4 +4.0 16.0 25.5 0.5 Worst breaking(Sea-side armor)
5 +4.0 18.0 25.6 1.0 Worst breaking(Sea- and harbor-side armor)
6 -1.0 18.0 21.0 0.25 Worst breaking(Sea-side armor)
7 -1.0 16.0 19.5 0.25 Worst breaking(Sea-side armor)
Table 2
Hydrograph B
Test Wave Prototypeswl Period Height Duration
Step ft mllw sec ft hr Wave Type
-1.0 16.0 9.0 0.25 Shakedown
1 -1.0 16.0 16.0 0.25 Worst breaking
2 -1.0 18.0 18.0 0.25 Worst breaking
3 +4.0 16.0 20.5 1.00 Worst breaking
4 +4.0 18.0 21.5 1.00 Worst breaking
5 -1.0 18.0 18.0 0.25 Worst breaking
6 -1.0 16.0 16.0 0.25 Worst breaking
-
Table 3
Hydrograph C
Test Wave Prototypeswl Period Height Duration
Step ft mllw sec ft hr Wave Type
+4.0 16.0 15.0 0.25 Shakedown
1 +4.0 16.0 30.5 1.00 Worst breaking
2 +4.0 18.0 34.0 1.00 Worst breaking
Table 4
Hydrograph D
Test Wave Prototypeswl Period Height Duration
Step ft mllw sec ft hr Wave Type
+4.0 16.0 15.0 0.25 Shakedown
1 +4.0 16.0 29.0 1.00 Worst breaking
2 +4.0 18.0 29.8 1.00 Worst breaking
1.
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AD-AI20 181 ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG--ETC F/G 13/2KAHULUI BREAKWATER STABILITY STUDY, KAHULUI- MAUI, HAWAII. HYOR -ETCIU),JUL/82HD_ G MARKLE.
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APPENDIX A: NOTATION
A Area, ft2
H Wave height, ft
L Length, linear scale, ft
mllw Mean lower low water
S Specific gravity
sta Station, surveying location where observations are taken
swl Still-water level
T Wave period, time, sec
V Volume, ft3
W Weight of individual stone or armor unit, lb
q Specific weight, pcf
Subscripts
a Refers to the ratio of model to prototype quantities
m Refers to model quantities
p Refers to prototype quantities
r Refers to armor stone or armor units
w Refers to water in which structure is situated
1-5 Refers to different sizes and types of construction material
J-[
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In accordance with letter from DAEN-RDC, DAEN-ASI dated22 July 1977, Subject: Facsimile Catalog Cards forLaboratory Technical Publications, a facsimile catalogcard in Library of Congress MARC format is reproducedbelow.
Markle, Dennis G.Kahului Breakwater Stability Study Kahului, Maui,
Hawaii : Hydraulic Model Investigation / by Dennis G.Markle (Hydraulics Laboratory, U.S. Army EngineerWaterways Experiment Station). -- Vicksburg, Miss. : TheStation ; Springfield, Va. : available from NTIS, 1982.
132 p. in various pagings, 22 p. of plates ; ill.27 cm. -- (Technical report ; HL-82-14)Cover title."July 1982."Final report."Prepared for U.S. Army Engineer Division, Pacific
Ocean."
1. Breakwaters. 2. Harbors--Hawaii. 3. Hydraulicmodels. 4. Kahului Harbor (Hawaii). I. United States.Army. Corps of Engineers. Pacific Ocean Division.II. U.S. Army Engineer Waterways Experiment Station.Hydraulics Division. III. Title IV. Series:
Markle, Dennis G.Kahului Breakwater Stability Study Kahului ... 1982.
(Card 2)
Technical report (U.S. Army Engineer WaterwaysExperiment Station) ; HL-82-14.TA7.W34 no.HL-82-14
1I